Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!utgpu!watserv1!watcgl!electro!eric
From: eric@electro.com (Eric)
Newsgroups: sci.electronics
Subject: Re: Spark Coils
Summary: good luck
Message-ID: <2082@electro.com>
Date: 6 Jul 90 14:23:23 GMT
References: <9007032018.AA27882@ucbvax.Berkeley.EDU>
Reply-To: eric@electro.UUCP (Eric)
Organization: Electrohome Ltd., Kitchener, ON
Lines: 19


Oil furnace transformers can apparently give 50kv sparks and up
while car ignition types give 35kv.  To get some real sparks you
need a Tesla coil.  To do this you need to make your own transformer
on a carboard form with some hi-V insulation and an oscillator
driving a high V high I primary winding with a very fast slope on
the rising and falling edges.  Apparently it can be done with tubes.
I do believe that transistors would go up in smoke with the back
emf so perhaps a moderate voltage (100v pk) feeding a spark thru
a neon or other type of flash tube?  I have tried a tube oscillator
back many years ago but I believe that high voltage leakage in my
tansformer prevented it from working.  
  Note: oil burner transformers are very dangerous.  I have had
  pulled muscles, burns and bruses from being thrown.  One side
  of the secondary is always grounded so you can not stack them
  for higher voltage but perhaps it could be done with car ignition
  coils?  It would probably be easier to get a high perf ignition coil
  and driver to get 50+ kv.
	  Eric